Pierrard Julien, Donnay Lorraine, Collard Alix, Van Ooteghem Geneviève
Institut de Recherche Expérimentale et Clinique (IREC), Center of Molecular Imaging, Radiotherapy and Oncology (MIRO), Université Catholique de Louvain, Brussels, Belgium.
Department of Radiation Oncology, Cliniques Universitaires Saint-Luc, Brussels, Belgium.
Clin Transl Radiat Oncol. 2025 Jul 13;54:101014. doi: 10.1016/j.ctro.2025.101014. eCollection 2025 Sep.
In locally advanced rectal cancer (LARC), increasing the complete response (CR) rate after total neo-adjuvant treatment may increase the patient eligibility for non-operative management ("watch and wait", W&W). Although a radiotherapy (RT) boost to the primary tumour may enhance CR rates, clear guidelines are currently lacking. This systematic review and -analysis investigate the technical parameters used for rectal boost RT and assess their impact on oncological outcomes.
Following PRISMA guidelines, the terms "rectum," "radiotherapy," and "boost" were searched in PubMed and EMBASE (PROSPERO: CRD42023444685). Studies reporting on external beam RT boost to the primary tumour in LARC and meeting quality criteria were included. Descriptive analyses extracted data on RT technique, preparation, boost delineation, dose, chemotherapy, and follow-up. A mixed-effects -analysis model evaluated the impact of selected parameters on CR and local recurrence rate (LRR). Studies were analysed separately based on treatment intent: planned surgery or W&W.
Out of 3904 references, 83 were included in the descriptive analysis and 78 in the -analysis. Substantial variability in RT parameters was observed across studies. Pathologic CR rates were significantly higher with intensity-modulated/volumetric-modulated arc RT (IMRT/VMAT, p = 0.007), simultaneous boost (p = 0.020), dose escalation (Biological equivalent dose > 74 Gy, p = 0.035), and the combination of induction and consolidation chemotherapy (p = 0.023). No significant associations were found for clinical CR or LRR.
While rectal RT boost is already part of real-world practices, the wide heterogeneity in techniques highlights the urgent need for standardisation. Our -analysis suggests that IMRT/VMAT, simultaneous boost, and dose escalation are associated with higher pathological CR rates and should be considered in future rectal boost guidelines. These findings, however, warrant careful interpretation due to the absence of adjustments for clinical, tumoral, or patient-related parameters that may also influence response rate and oncological outcomes.
在局部晚期直肠癌（LARC）中，提高全新辅助治疗后的完全缓解（CR）率可能会增加患者接受非手术治疗（“观察等待”，W&W）的可能性。尽管对原发肿瘤进行放疗（RT）增敏可能会提高CR率，但目前缺乏明确的指南。本系统评价和分析旨在研究直肠增敏RT所使用的技术参数，并评估其对肿瘤学结局的影响。
按照PRISMA指南，在PubMed和EMBASE中检索“直肠”“放疗”和“增敏”等术语（PROSPERO：CRD42023444685）。纳入报告LARC中原发肿瘤外照射RT增敏且符合质量标准的研究。描述性分析提取了关于RT技术、准备、增敏勾画、剂量、化疗和随访的数据。混合效应分析模型评估了选定参数对CR和局部复发率（LRR）的影响。根据治疗意图对研究进行单独分析：计划手术或W&W。
在3904篇参考文献中，83篇纳入描述性分析，78篇纳入分析。研究间RT参数存在很大差异。调强放疗/容积调强弧形放疗（IMRT/VMAT，p = 0.007）、同步增敏（p = 0.020）、剂量递增（生物等效剂量>74 Gy，p = 0.035）以及诱导化疗与巩固化疗联合使用（p = 0.当直肠RT增敏已经是实际临床实践的一部分时，技术上的广泛异质性凸显了标准化的迫切需求。我们的分析表明，IMRT/VMAT、同步增敏和剂量递增与更高的病理CR率相关，应在未来的直肠增敏指南中予以考虑。然而，由于未对可能也影响缓解率和肿瘤学结局的临床、肿瘤或患者相关参数进行调整，这些发现需要谨慎解读。 023）时，病理CR率显著更高。临床CR或LRR未发现显著相关性。
